This invention relates to water soluble reaction products prepared by the oxidative polymerization of quaternized 5,6-dihydroxyindole-2-carboxylic acid amides or esters, to compositions containing such products, to methods of coloring hair or treating skin utilizing the compositions and to kits containing the compositions. More specifically, the invention relates to reaction products characterized by a quaternary nitrogen substituent and to intermediates useful for the preparation of the reaction products.
The reaction products of this invention are mixtures of many compounds formed by the oxidative polymerization of the aforementioned amide or ester derivatives of 5,6-dihydroxyindole-2-carboxylic acid (DHICA). The oxidative polymerization of DHICA and certain of its selected derivatives is described in commonly owned U.S. Pat. No. 5,346,509, the disclosure of which is incorporated herein by reference. The particular DHICA derivatives which are oxidatively polymerized to form the products of this invention are neither described nor suggested in the '509 patent.
To facilitate understanding of this invention, the following system will be employed in its description:
A: The oxidative polymerization products should be understood to be the reaction products of the invention. In addition to the term "reaction products of the invention", they are sometimes referred to as hair colorants, hair dyes or skin treatment products and, often, melanin like products of the invention.
B: The quaternized products formed by reaction of DHICA with selected quaternary compounds to be described more fully hereinafter are referred to as "intermediates" or as "intermediates of the invention".
C: Compositions of the invention may take several forms depending on their intended use. If the products of the invention are to be directly added to the hair, they will be formed on the hair by oxidative polymerization of intermediates of the invention in an aqueous media. If they are to be employed for skin care they may be aqueous, non-aqueous or they may be mixtures of polar or non-polar organic solvents and may be either free flowing or viscous.
Notwithstanding their melanin-like properties, the reaction products of this invention are not true melanin derivatives. The reaction products of the present invention are mixtures of many compounds and thus cannot be precisely defined by a chemical formula. Accordingly, they will be defined herein by their method of preparation. It is believed that the mixture of the compounds comprising the reaction products of this invention includes some dimers, trimers and tetramers of the intermediates. However, most species are oligomers and many are probably true polymers. Surprisingly, they have substantially similar hair coloring and other properties compared to the melanin derivates described in U.S. Ser. No. 568,056 (CP1141).
Naturally-occurring melanin is the pigment that gives hair its color. A general discussion of the properties and chemistry of melanins may be found in Prota, G., "Progress In The Chemistry of Melanins And Related Metabolites", Mcd. Res. Reviews, 8:525-56 (1988) and Moncrieff, R. W., Manufacturing Chemist, 8, 330-34 (August 1950). The gradual reduction of melanin formation with age causes hair to become gray.
Naturally-occurring melanin pigment itself is unacceptable for use in a hair dye composition because it is easily removed by rinsing or rubbing and leaves the hair feeling rough. One present method for coloring gray hair involves the use of naturally-occurring melanin precursors such as DMI that when combined with an oxidant, form useful melanin like pigments. See, for example, U.S. Pat. No. 3,194,734 (Seemuller et al.), U.S. Pat. No. 4,808,190 (Grollier et al.), and U.S. Pat. No. 4,888,027 (Grollier et al.). See also U.S. Pat. No. 5,346,509 (Schultz et al.) which describes the conversion of DHICA to melanin like pigments.
The primary disadvantage is that the hair colors initially produced with melanin precursor dyes are undesirable achromatic colors (cold grays and blacks). Hair dyed with these colorants must undergo a second treatment step with an oxidant such as hydrogen peroxide to achieve natural chromatic colors (warm yellows, reds, and browns). See, for example, U.S. Pat. No. 3,194,734 (Seemuller et al.). In addition, melanin precursors are expensive and, because they are highly reactive, are difficult to work with. The use of melanin precursors also can result in undesirable scalp and skin staining.
Furthermore, because the pigments are formed from the melanin precursors in the hair shaft the hair colors produced using the melanin precursors are permanent. The hair color must grow out to return to its original color. Often, consumers prefer to use a temporary hair color that will wash out after one or two shampoos.
The compositions described in PCT patent application Ser. No. US93/11174 filed Nov. 17, 1993 are usefull as temporary hair colorants. These compositions contain melanin derivatives prepared by forming a complex between a water soluble anionic melanin with selected quaternary compounds, suitably alkyltrimonium halides, alkylalkonium halides or dialkyldimonium halides such as cetrimonium halide or stearalkonium halides. These complexes impart a temporary coloring to human hair when deposited thereon in aqueous compositions and thereafter dried. Although such compositions are acceptable to many consumers, they may not be acceptable to others because they wash off the hair too readily. Only rarely do they survive a single shampoo. In fact, normally they require a "leave on" treatment since they may be readily removed with even a water rinse.
The art has sought hair coloring compositions providing colors that are not as difficult to use as the melanin precursors or as permanent dyes, but are more permanent than the colors provided by the above described temporary hair colorants, i.e. dyes which will survive 4 to 6 shampoos or can be mixed with additional dyes in a shampoo base in order to freshen temporary hair colors. The hair colorants utilized in the compositions of this invention have these desirable properties. In that respect they are similar to the products of the above identified U.S. Ser. No. 568,056 (CP-1141), but are prepared differently.
The compositions of this invention produce in a single treatment step semi-permanent natural-looking hair color that resist fading in sunlight, resist rub off and resist bleeding in contact with water. The compositions are inexpensive and simple to work with. It has surprisingly been found that aqueous compositions containing the reaction products of this invention will, when applied to hair, impart a semi-permanent color to the hair which will survive more than three shampoos without substantial loss of color characteristics. A particular advantage of the reaction products of this invention is that they can be combined with other hair colorants in a shampoo base to freshen the existing hair color whereby the hair color is renewed and retained for an appreciably further period of time. Another is that the reaction products can be used for simultaneous coloring and conditioning of hair.
The products of this invention are also useful for skin care. They may be used alone or, preferably, in conventional skin care compositions. When so employed, they function both as skin colorants to impart a tanned appearance to the treated skin and as sun screen agents to protect the skin from harmfull infrared rays.
With both skin and hair, the products exhibit the other attributes of natural melanin, i.e., they are antioxidants and free radical scavengers and minimize hair damage caused by oxidants and free radicals often present in the hair after atmospheric exposure.
U.S. Pat. No. 5,006,331 (Gaskin) discloses the use of melanin compositions containing triethanolamine and ferric chloride. The resultant mixture of melanin, triethanolamine and ferric chloride is said to be useful for skin protections, for wound healing and for strengthening hair. An alternate composition contains trypsin in an alkaline medium. Melanin is present in the skin protectant compositions of Gaskin in an amount of from about 0.001 to about 0.09%, along with from about 0.0001% to about 0.27% ferric chloride, both being on a weight basis based on total weight. The skin protectant composition further contains up to about 5% by weight triethanolamine. While not providing a range of concentration for the amount of melanin hydrolysate for the hair protectant compositions according to her invention, Gaskin states at column 6, line 30 that it is present therein in an amount of only about 0.0015% by weight of the total composition. However, this level of Gaskin's melanin hydrolysate is wholly insufficient to impart a color to hair. Moreover, neither of Gaskin's methods provide a melanin material of a cationic character.
PCT Application WO 91/17738 discloses the use of soluble melanin derivatives in a process for producing lightly colored melanins that are aesthetically suitable for use in cosmetic compositions.
WO 94/25532 describes melanin linked to a lipid to form a lipomelanin and its use in a sunscreen product.
It is an object of this invention to provide an aqueous composition for semi-permanently coloring hair using water soluble melanin like products of the invention.
It is also an object of this invention to provide compositions that will produce a semi-permanent natural-looking hair color that resists fading in sunlight, will not rub off, and will not bleed when in contact with water.
It is further an object of this invention to provide inexpensive compositions for semi-permanently coloring hair using water soluble melanin like products of the invention.
It is also an object of this invention to provide compositions that are simple to work with for semi-permanently coloring hair using water soluble melanin like products of the invention.
It is also an object of this invention to provide a one-step process for semi-permanently coloring hair.
It is a further object of this invention to provide a composition for simultaneously coloring and conditioning hair.
It is a still further object of this invention to provide compositions which when used with appropriate shampoos are usefull for freshening hair colors.
It is a still further object of this invention to provide novel melanin like products of the invention and compositions thereof for skin care.
It is a still further object of this invention to provide novel intermediates useful for the production of melanin like products of the invention.